For decades, parents would bring their newborn babies to Helen Schlie's bookstore so their infants could touch a first edition copy of the Book of Mormon. Missionaries from around the world were also drawn to the Mesa, Ariz. bookstore where they took pictures with the 182-year-old book. Some would even cry, Schlie said.

But on Monday, the 88-year-old shop owner discovered that the sacred text, which Mormons hold in equal reverence with the Bible, had been stolen from an unlocked file cabinet in the back office of her bookstore, Rare and Out of Print Books and Art. The book is valued at $100,000.

"So many people know where the book was. I've never had it under glass. I've always let people touch it and hold it and take pictures with it," she told ABCNews.com.

Schlie does not have security cameras in her store, but has a night watchman. She said she pinpointed a 20-minute window of time when her guard took a bathroom break that the theft must have occurred.

Her store is one block from the Mormon Temple in Mesa.

"It's a well traveled neighborhood," she said.

The Mesa Police Department said it is investigating the theft.

Several years ago, Schlie decided to tear out pages from the book and sell them for $2,500 to $4,000 apiece. The pages are mounted in handmade frames.

"Each page is capable of touching hundreds of thousands of lives," she said.

She sold between 40 and 50 pages from the book before it was stolen.

Schlie converted to Mormonism when she was a grandmother living in Michigan and said she once filled in as a substitute teacher for the Sunday school class of 15-year-old Mitt Romney.

Anyone with information about the missing book is asked to contact the Mesa Police Department.